Because of inherent risks associated with using an elevator during a fire, elevator systems are currently underutilized as evacuation vehicles. However, in a large multistory building, such as a high-rise, skyscraper, and some mid-rises, an elevator may present the only viable means of escape. This reality became all too apparent to the witnesses of the 9/11 terrorism attack who watched in horror as occupants of the upper floors of the twin towers jumped out of windows to their deaths.
There is typically a brief period of time between the initial detection of the fire and the point when combustion produces dangerous amounts of smoke and toxic fumes, in which the elevators of the building could be safely used to evacuate a fire zone of the building.
Up until 1973, elevators remained active during a fire, permitting a car full of people to arrive at the fire floor with tragic results. Because of this dangerous situation, Phase I—Emergency Recall Operation is now required on all U.S. elevators by ASME A17.1 Safety Code for Elevators and Escalators. Phase I is initiated automatically by the detection of smoke in an elevator lobby or initiated manually with a security key by the fire department from the ground floor lobby.
Phase II—Emergency In-Car Operation is also required to allow the fire service override access to the car. Phase II is used only when the hoistway is free from both smoke and water and when reliable power is available.
The U.S. Fire Administration estimates that every year more than 120,000 fires occur in buildings taller than three stories in height. Mid-rises, buildings between three and seven stories, account for the majority of these fire incidents. The annual occurrence of fires equates to one fire for every six U.S. mid-rise buildings currently in existence. High-rise buildings account for about 40,000 of these fires, or about one fire per existing high-rise per year. Most of these fires are in residential-type occupancies.
Due to the unfortunate frequency of false alarms, rampant skepticism regarding the validity of an alarm has added a layer of complexity and danger to the evacuation process. Many occupants will not leave a building that is on fire until they smell smoke or until a human voice orders them to evacuate. According to follow-up interviews with actual fire incident evacuees, the time from first hearing an alarm to beginning any evacuation may exceed thirty minutes.
Removing the elevator as an option for escape may be a death sentence to the elderly, the very young and the disabled. The fire stairs, which may offer an ideal means for evacuation to the able-bodied may not be a realistic option for many. Ambulatory elderly and children are slower to evacuate and may adversely affect their own and other occupants' evacuation time. People with permanent disabilities may not be able to evacuate at all. Temporarily disabled people, relying on crutches, leg casts or foot braces, may suffer the same plight as the permanently disabled.
Despite advantages associated with using elevators as a means of escape during an emergency, especially for a certain segment of the population, the Fire Protection Inspector Bill Kuehner has written: “In fire evacuation plans for high-rise buildings, the plans make a point to state that elevators are not to be used in the event of fire. For many, these plans may seem contradictory, because everyone wants to exit the building as quickly as possible, But there are significant reasons why people should not use an elevator during a fire evacuation.”
The Americans with Disabilities Act (ADA), which was enacted in 1990 to assure all people equal access to buildings used by the general public, does not provide a protected way out of buildings during building emergencies. People who cannot descend the stairs must wait for a firefighter and other first responder to rescue them. While typically a fire department response time is only six to seven minutes, it can take thirty minutes or more to reach people waiting in the fire zone.